File-sharing service WeTransfer now has 18 million active users each month and helps to deliver more than 2 million files on a daily basis.

From the browser, WeTransfer allows you to send a file up to 2GB in size, jot down a quick message and include your own email address for further correspondence. Neither party needs an account or specialized software – senders only need to be able to access the webpage, and recipients just have to follow the instructions in the email.

In October, WeTransfer helped its users share 46 million files, with 4,000 terabytes of data passing through the Amazon servers that it uses. For comparison, WeTransfer says that on a daily basis it now transfers the same amount as it used to in all of November 2010.

Launched in 2009, WeTransfer is based out of Amsterdam and San Francisco. The bootstrapped company relaunched its service in September this year, and co-founder Nalden says the company is now profitable “with nice margins.”